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I'm interested in having a Microcontroller trigger a device within a 1ms time of GNSS time every 100ms GNNS time.

What is the best approach to this problem?

Edit: I understand that GNSS may update at a one second rate or every 100 mS depending on the GPS unit used.

Russell McMahon
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FourierFlux
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    MS is mega siemens, maybe you mean within 1 ms? – John D Nov 11 '21 at 00:50
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    GNSS puts out a 1 Hz signal (it may be called PPS or pulse per second). You can use that PPS signal as an input to the micro. Each time PPS goes high, you launch a train of 10 pulses at 10 Hz using the microcontroller internal or external clock. Over 1 second, that should be accurate enough. The only catch is that you must always start a new pulse train when you see PPS go high, even if the previous pulse train was not quite finished. – user57037 Nov 11 '21 at 01:18
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    You can also type this phrase into a search engine "GPS disciplined oscillator." Maybe also "Numerically Controlled Oscillator." – user57037 Nov 11 '21 at 01:24
  • Have the PPS signal correct one of your timers. – Kartman Nov 11 '21 at 06:06
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    I’m voting to close Close & reopen - the questions are so tightly linked that they do not violate the single question rule. – Russell McMahon Nov 25 '21 at 07:50
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    VOTES TO CLOSE: When the "two questions" are so tightly linked and trivially different in context in would be "really nice" if even one of the vote-to-close ers instead decided to make the trivial edit to make the question more acceptable. – Russell McMahon Nov 25 '21 at 08:21

1 Answers1

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The simplest way would be to get a GNSS chip that supports a 10Hz timepulse output (also known as "PPS" when it's 1Hz, but several chips support configurable output frequency). Then your micro would just have to enable and configure that output.

hobbs
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